Jennifer Powell Graves spoke after receiving the Chain Breaker of the Year Award from the Chain Breaker Foundation, a non-profit foundation dedicated to stopping the cycle of domestic abuse, during a ceremony in Orem on Thursday, April 4, 2013. Graves is the sister of Josh Powell, who killed himself and his two sons after being a person of interest in the disappearance of his wife, Susan Powell.SPENSER HEAPS/Daily Herald6 hours ago • Cathy Allred - Daily Herald

"What an incredible woman. I couldn't make the choices she had to make," said Joan Shippen, founder and president of the Chain Breaker Foundation.

Susan Powell disappeared from her home in West Valley City in 2009. Her husband, Josh Powell and his father, Steven Powell, were persons of interest. In 2011, Steven Powell was arrested on voyeurism and pornography charges in Washington. Shortly after, Josh Powell lost custody of the couples' two young boys. In February 2012 during a supervised visit, he locked the social worker out of his house and killed his sons and himself by setting the house on fire.

Josh Powell's sister spoke out against her father and brother and their abusive behavior during the 3-year investigation.

Shippen talked about her experience in working with Graves on a video with KSL about breaking the chain of domestic violence. Graves appeared somewhat abashed by the attention.

"I'm just an average person, just like you guys," Graves said.

She said as a child she saw her father treat her mother increasingly poorly during their relationship.

"He was controlling and manipulative, and he was so angry all of the time and I don't know why," she said.

She said she believes abusive behavior can be addictive like pornography or drugs.

Hosted by the foundation at its Foundation House in Orem, the meeting was bittersweet and subdued.

Susan Powell's parents, Chuck and Judy Cox, serve on the foundation's advisory board but were not able to attend the presentation.

A box of tissues was passed through the small crowd of guests to wipe tears away after Jessie Funke finished a song named "Susan's Song: A Dream Away" written by Camilyn Morrison.

KSL produced a short clip featuring Shippen and Graves and their plea to stop abuse.

The director for the Utah Office on Domestic and Sexual Violence, Ned Searle, introduced the speakers and said a few words about violence in intimate relationships.

"More women die each day in this country as a result of intimate partner violence. More women have been killed by an intimate partner in the last half century than all the United States soldiers killed in the Vietnam War," Searle said.

Males perpetrate 95 percent of all serious domestic violence; 99.8 percent of those in prison convicted of rape are men, he said.

"Men need to become aware of the devastation and misery associated with violence, stop minimizing its seriousness, eliminate degrading stories in their conversations and quit allowing victims to be blamed when they are violated with violence. To begin the extinction of violence, men must take responsibility for its existence," Searle said.

For more information, go to chainbreakerfoundation.com or susancoxpowellfoundation.com.

West Valley City Police Chief Mike Powell told Salt Lake City's FOX 13 News that authorities are "looking for anything that might lead us to Susan."

"We have done everything we possibly can to follow up on those and conduct any additional investigation that may lead us to knowing and discovering where Susan is," Powell told the TV station.

Powell was reported missing by her family on Dec. 7, 2009, when she failed to show up for her job as a stock broker at Wells Fargo Financial in West Valley City, Utah. She was 28 at the time. Her husband, Joshua Powell, told police he had been camping with their two children, ages 2 and 4, and had last seen his wife around midnight.

Suspicious of his story, investigators named Powell a "person of interest" in his wife's disappearance. Several search warrants were served, including one to draw biological samples from him. Police also impounded the family van.

Joshua Powell killed himself and the couple’s two children in a house fire in February 2012.

Bremner said help is needed to search the large farm in Oregon for clues.

"We need volunteers and cadaver dogs to go to the site," Bremner said.

To volunteer for the search, contact Bremner via her website, [You must be registered and logged in to see this link.]

No one has been charged in Susan Cox Powell's disappearance. Police said the case remains an active investigation.[You must be registered and logged in to see this link.]

Thanks Raine. I saw this on facebook this morning. So far they have found nothing. When I searched for more information I found a story about Josh brother committing suicide. I have not had time to see if that story was posted here.

After a two-day search in rural Oregon failed to yield any trace of missing Utah mother Susan Powell, authorities said Thursday they may close the investigation.

"The leads have become fewer and farther between," said Wayne Pyle, the city manager for West Valley City, Utah.

"If nothing comes from it, we do feel like we are close to the end of the investigation," he said.

Investigators found no signs of Powell, missing since 2009, after using dogs to search a rural site near this town in Western Oregon.

"It's been a meticulously investigated case. We've looked at every tip and aspect" and will continue to do so, said Sgt. Mike Powell, a spokesman for West Valley City police who is not related to the missing woman.

In an interview Wednesday night, Susan Powell's father said he hoped the investigators would turn up some sign of her.

"I'm disappointed," said Chuck Cox, who accompanied some of the search dogs on the hunt. "I just don't know where she is, but we'll keep looking for her."

He said the Oregon property had ties to the family.

Susan Powell was reported missing in December 2009 after she didn't show up for work. Her husband, Josh, maintained his innocence and said he took the couple's young boys on a midnight camping trip in freezing temperatures the night his wife disappeared.

In February 2012, Josh Powell locked a social worker out of his home at the start of a supervised visit, then killed himself and the couple's two young children, attacking his sons with a hatchet and then setting the house ablaze. Days earlier, a court had ordered Powell to undergo an intensive psychosexual evaluation as part of a custody dispute.

Josh Powell was never charged in his wife's disappearance, but unsealed documents say authorities found Susan Powell's blood on a floor next to a sofa that appeared to have been recently cleaned, with two fans set up to blow on it. Investigators also found life insurance policies on Susan Powell and determined that Josh Powell had filed paperwork to withdraw her retirement account money about 10 days after her disappearance.

Anne Bremner, an attorney for the Cox family, said the brother of Josh Powell had said in a deposition that he had driven to Oregon and abandoned a vehicle there. The brother, Michael Powell, committed suicide earlier this year.

The Oregon property that was searched is on a narrow road that juts seven miles into forestland before reaching a dead-end.

"Last couple days have been quite a spectacle with the news media and the helicopters," said neighbor Robert Perkey. "I was up till 1:00 last night with all the commotion and they were back this morning."

Perkey said the people living in the house are renters who moved in recently.

Bremner said she's still interested in seeing more work at the property, including the possibility of having volunteers go to the site to help search.

Cox said he appreciated that investigators spent time on the Oregon search, saying it showed a dedication and determination to find his daughter.

When Utah police led 20 searchers and five cadaver dogs onto a property in Salem, Ore., this week, they were acting on suspicions that Susan Cox Powell was buried there – and that the man who buried her was not her late husband, Josh Powell, but rather his brother, a politician and graduate student who later committed suicide.

Susan's father, Charles Cox – who has worked tirelessly with authorities to find his daughter – shares with PEOPLE that West Valley City, Utah, police believe Josh's brother, Michael Powell, was an accomplice in her murder.

According to Cox and other sources, detectives believe Josh drove the couple's Town & Country van hundreds of miles northwest in a snowstorm in December 2009 as his and Susan's two young sons, Charlie and Braden, slept in the backseat. They believe Josh turned Susan's body over to Michael, who buried her.

But this week's search on a woodsy, 180-acre property that was rented by Josh's relatives at the time of Susan's disappearance did not yield any human remains and the search was called off Thursday after three days.

Michael Powell "was more involved in the disposal of her body," says Cox, who has endured years of searches that have come up empty and been notified repeatedly of the discovery of remains that turned out not to be Susan's.

Cox says the police are at the end of their investigation and might soon discuss their suspicion of Michael's involvement.

A West Valley City police spokesman, Sgt. Mike Powell (no relation), would neither confirm nor deny that police now believe Michael Powell buried Susan's body. But he confirms that police may soon reveal more about Susan's disappearance.

He added that information about the case should only be treated as factual once it's released by the police department. "Any particular aspect of the investigation not coming from the WVCPD should be examined very cautiously," Sgt. Powell said.

The Early InvestigationJosh and Michael Powell’s sister, Jennifer Graves, who has publicly shared her suspicions about Josh since early in the case, tells PEOPLE that she always suspected that Michael was at least aware that Josh killed Susan.

Now, after further discussing Michael with other family members, she also suspects he was an accomplice to the murder.

"It's very possible that he helped Josh, yes," says Graves, who says the revelation has left her heartbroken. "It makes me sad to think he could have sunk so low. Growing up, Michael was a sweet little kid, very loving and a joy to be around."

She adds that this latest development helps her understand his possible motivations for taking his own life.

"Perhaps he got wind of something [that the police learned] and decided he couldn’t keep it covered up much longer," Graves offered. "Or perhaps he was just weighed down with a great deal of guilt that finally caught up with him."

Early in the case, after Josh claimed that Susan simply took off while he and the boys went on a weekend camping trip in a blizzard, police named him a person of interest. The West Valley City police department was recently forced to return federal drug-enforcement grant money that it improperly spent on the Powell case – money that may have been used to investigate whether Josh poisoned Susan's pancakes, according to media reports.

During the strange twists and turns in the past 3½ years, police seemed to focus their suspicions mostly on Josh and his father Steven.

Josh is now dead, having killed himself and his sons in an intentional house explosion last year. Steven is serving time for secretly photographing 8- and 9-year-old girls who lived next door. Many images of Susan and journal entries about her also turned up in Steven's house, which was searched repeatedly after Josh and sons Charlie and Braden moved in.

But there has been little focus publicly on Michael, a Democratic National Convention delegate for President Obama who ran unsuccessfully for a state representative seat in Washington state.

In an email to PEOPLE a month after Susan's disappearance, Michael, a doctoral candidate in cognitive science at the University of Minnesota, ardently defended his "grief-stricken" brother, complained about the "level of integrity" by the media, and suggested police look outside his family for suspects, particularly at a neighbor of Josh and Susan's in West Valley City, Utah.

"As someone who is close to Josh, I know he is hurting because he misses his wife, and my hope for him is that people are understanding of that," Michael Powell told PEOPLE on Jan. 16, 2010.

Powell said he drove 1,000 miles to help Josh after Susan's disappearance because "I am happy to help a family member in need."

Two years after Susan's death, Josh Powell adjusted a $1.5 million insurance policy on his sons to name Michael Powell as a 93 percent beneficiary. At the same time, during custody hearings, police would repeatedly tell Charles Cox that Josh's arrest was imminent.

In February 2012, Josh Powell, frustrated after losing primary custody of his sons to Susan's parents, blew up his rental house after the boys were dropped off for a visit, killing all three of them.

Michael Powell's SuicidePolice began seeing clues to Michael Powell's involvement fairly early in the case, says Anne Bremner, a high-profile Seattle attorney. Bremner represents Susan's family as well as the victims in Steve Powell's voyeurism case. She also has participated in many discussions between police and the Cox family.

Bremner says police learned after Susan disappeared that "Michael had his Ford Taurus towed a hundred miles, and then sold it for salvage value because, police think, he had her body in there. Then he hired militaristic satellite photography people to go look at the wrecking yard to see if his car had been completely destroyed, but it wasn't."

She adds, "Cadaver dogs came to the tow yard and only indicated on his car, no one else's."

More recently, Bremner says, Utah police repeatedly questioned Michael Powell in Minneapolis. Then, three months ago, Michael Powell jumped from the fifth story of a parking structure, taking his own life. He was 30.

Cox says he and the officers believe Michael Powell "couldn't live with what he'd done, or the police were closing in." But Cox also said it was he who prompted the search in Salem, Ore., based on a tip he received from a confidential source.

With this latest search completed, Cox says the West Valley City police tell him there will be no more searches and their investigation is finished. Sgt. Powell says the department will do more if new leads spring up, but "we are nearing the end of the tips and leads that we have to follow up on."

He adds, "Our focus has been finding Susan, and Susan is still missing. It's been a long, enduring and difficult investigation."

But Cox vows "we'll keep searching" until he finds his daughter.

Bremner says Cox is so convinced that Michael Powell buried Susan in the Salem, Ore., area that he's organizing a search for the weekend of May 25 on public lands surrounding the Salem property, and he already has recruited more searchers than the number that participated in this week's effort.